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Titre : Influencia de los recursos antropogénicos en la abundancia y dieta del babisuri (Bassariscus astutus saxicola Merriam, 1897) en el complejo Insular Espíritu Santo, B.C.S.,México.

Auteur : Sansores Sánchez, Rigel Eduardo

Etablissement de soutenance : Centro de Investigaciones Biológicas del Noroeste (CIBNOR)

Grade : Maestría en Ciencias en el Uso, Manejo y Preservación de los Recursos Naturales 2016

Résumé
The main strategy for the conservation of the insular biodiversity, has consisted in declaring these ecosystems as Natural Protected Areas (NPA). Currently, the Insular Complex, Espiritu Santo, is the main natural destination in La Paz and the islands of the Sea of Cortez. And, every year, these NPA are visited by a great number of people, due to the increase of the tourism industry. However, human activity is the main threat to terrestrial´s biota in these ecosystems. In this insular environment lives the ringtail (Bassariscus astutus saxicola) an endangered subspecies and a unique native endemic carnivore in the island with a limited awareness about its ecology. This paper evaluates the influence of anthropogenic food on the diet and abundance of the ringtail in 8 locations of the Insular Complex, grouped together according to their level of anthropogenic concurrency (high and low) by scat analysis, in order to determine the relevance of these resources as well as the abundance of the species, by capturing and evaluating its body condition. In addition, the habitat of the ringtail was defined based on the environmental variables of the sites located on the western side of the insular complex. The results showed that arthropods and plants were the most important elements on the diet. Being the orthoptera and fig (Ficus palmeri) of major consumption, reaching both of them a 43.86 % of consumption, while the anthropogenic resource was a less important category with a 1.26 % of consumption. No significant differences in diet were found between seasons and sites with different levels of anthropogenic use or between individual sites (P = > 0.05). The greater abundance of the ringtail was registered in Candelero and Mesteño sites (17 and 9 individuals respectively) unlike the lower abundance of Gallo and Ballena sites (1 and 3 individuals, respectively), determining a ratio of sexes in the Insular Complex of 1.63 males for each female. The evaluation of body condition of the ringtails, showed that the captured individuals enjoy of good or regular condition (51 % and 42 % respectively), while only 7 % were in bad condition. A principal component analysis with environmental variables, showed a preference of ringtails for sites with larger rocks and greater coverage of zalate, presenting the Candelero and Mesteño sites these characteristics, which is consistent with the highest abundance in these sites.

Mots Clés : Bassariscus astutus saxicola ; Espíritu Santo ; recursos antropogénicos ; abundancia ; condición corporal

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